Javan Mynas – fledging period

The pair of Javan Mynas (Acridotheres javanicus) in my garden is making its presence felt by the constant begging calls of a recently fledged juvenile. This has been going on for some weeks now.

Whenever I was in the garden, the two adults will be there with a noisy juvenile in tow. So this evening I decided to document the feeding of the juvenile by the attending adults just for curiosity sake.

Video grab
video grab

I left some pieces of bread on the ground and kept my video cam rolling nearby. Immediately the noisy juvenile flew in followed by an adult. The latter picked up a piece of bread and fed the juvenile who swallowed it. The adult then picked up a larger piece and offered it to the juvenile but not actually passing it to the latter (above).

Video grab
video grab

With its beakful of bread piece, it then pretended to pick up another piece. Again it offered it to the juvenile but withdrew at the last moment (above). The adult kept on picking up or pretended to pick up pieces of bread (it had its beak full and could only manage to pick up small pieces) as if to demonstrate to the juvenile what the latter should do – see video below.

During this period the mate flew in, picked up a piece and flew off. The juvenile was only able to pick up a very small piece for itself.

Video grab
video grab

Four days later the family of Javan Mynas returned to forage in the grassy areas of my garden. This time the two adults and the juvenile foraged mainly on their own. The begging cries of the juvenile were ever present (above) but the adults fed on their own (below) and only fed the former a few times.

Video grab
video grab

The juvenile was obviously well on the way towards becoming independent of the adults as it was able to find food for itself (see video below). According to aviculturist Lee Chiu San, “It is a fact that many birds, especially mynas and parrots, will continue to beg and insist on being fed long after they are capable of feeding themselves.”

It would appear that this was towards the end of the fledgling period, otherwise the adults would continue feeding the juvenile most of the time.

I regret not noting the date the juvenile first appeared, as I would then be able to gauge how long it was since fledging.

I was confident the fledgling period (number of days from leaving nest to being independent of parents) would be in the local literature. After all, it is a very common species and birdwatchers, having been around for half a century or more, should have recorded the information somewhere. But I only managed to find the fledgling period of 22-24 days for the Common Myna (A. tristis) LINK.

The next time a begging juvenile Javan Myna appears in my garden, I will definitely note down the date and follow up until the usual pair returns minus the juvenile.

YC Wee & Lee Chiu San
Singapore
31st March 2017

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